Modular polyoxometalate-layered double hydroxides as efficient heterogeneous sulfoxidation and epoxidation catalysts

摘要

Selective sulfoxidation of sulfides and epoxidation of olefins are two types of important organic reactions and the corresponding products of sulfoxides, sulfones and epoxides are widely used as raw materials in industrial processes. The fabrication of one efficient catalyst for both reactions, remains a challenging task. In this paper, we report the preparation of a highly efficient heterogeneous catalyst of Mg3Al-ILs-La(PW11)2 using an exfoliation/assembly approach. The catalyst was characterized by FT-IR, XRD, TG/DTA, BET, XPS, 29Si CP/MAS NMR, the 27Al-MAS NMR, SEM, HRTEM, EDX etc. The designed catalyst showed high efficiency and selectivity for sulfoxidation of sulphides and epoxidation of olefins under mild conditions at a production rate of 208 mmol g-1 h-1 and 31 mmol g-1 h-1, respectively. Moreover, the Mg3Al-ILs-La(PW11)2 can be recycled and reused at least 5 times without obvious decrease of its catalytic activity. The scaled-up experiments revealed that the catalyst retained its efficiency and robustness, demonstrating the catalyts' great potential for industrial applications.